To the Editor.—Dr Blankenhorn and colleagues1 presented angiogram data from analysis of the placebo cohort of the Cholesterol Lowering Atherosclerosis Study indicating that the increasing consumption of total fat; polyunsaturated fat; and lauric, oleic, and linoleic acids was associated with a subsequent increase in the risk of developing new coronary artery lesions. The association of new lesions with increasing consumption of total fat and lauric acid is not surprising. On the contrary, the association of new lesions with increasing consumption of polyunsaturated fat and oleic and linoleic acid is perplexing.A recent large-population, cross-sectional study suggested that the consumption of polyunsaturated and monounsaturated fat was associated with a lower coronary risk profile.2 The Seven Countries Study demonstrated a significant association with entry dietary oleic acid intake and decreased all-cause and coronary heart disease mortality at 15 years.3 Other studies have suggested beneficial effects on lipoprotein metabolism